PROS1 and infection: Seeking a convenient human cell line in which to further explore the anti-HSV-1 activity of our CRISPR/Cas9 system, we found that the human oligodendroglioma cell line TC62034 robustly supported HSV-1 replication at low and high multiplicities of infection, as evidenced by expression of ICP0, the early viral protein ICP8, which is involved in viral DNA replication and late gene transactivation35, 36, 37, and the late envelope protein, glycoprotein C, which enhances infectivity of the virus38 (Fig. S3A–D).